SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00d56320aa27974d507902658e71fa49a354d63715e7e0ed37d131cecb31fa56' 
  AND token = '8YHxgO8ur/Mbf5q/uTphKvwVsBjtRqYTST2x652OAzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}